The rate of tooth decay has increased substantially in young children, particularly among ethnic minorities and those from low-income families. This increase is due, in large part, to poor oral hygiene and associated behaviors. Although promising interventions exist to promote behavior change in this regard, these programs focus almost entirely on teaching parents or children tooth brushing technique, without regard for behavior management and motivational strategies. To address this gap, and in response to RFA-DE-12-001, we plan to develop a brief parent-focused intervention that addresses both the technical and behavioral aspects of tooth brushing interactions. Based on existing behavioral interventions for child behavior problems, this intervention will teach parents how to brush their child's teeth as well as how to manage child non-compliance during brushing and how to encourage the child's transition to independent tooth brushing. We anticipate that such an intervention will lead to more lasting improvements in child oral health, particularly among those with special healthcare needs or behavior problems that complicate child behavior management. In this treatment development study, we propose to develop and test an observational tool to be used as a method for identifying targets for intervention and as a primary outcome measure in intervention research. Participants will include 132 children ages 24 to 60 months and their primary caregivers, recruited from the Center for Pediatric Dentistry (CPD). These data will be used to establish the reliability and validity of the measure, to examine differences in parent-child tooth brushing interactions as a function of child, parent, and family characteristics, and to support the theoretical rationale and presumed mechanisms of action underlying our proposed intervention. Other tangible 'products' from the study include the development of our investigative team, featuring new collaborations between UW and SCH dentists, dental researchers and developmental psychologists; preliminary data to support the feasibility of recruiting low-income, ethnically diverse families through the CPD clinic; and a study protocol and treatment manual with interventions that will follow from the observational data collected in this first phase of our research. These data will provide the foundation for a randomized controlled trial (RCT) testing the efficacy of a novel, parent-focused behavioral intervention to improve early childhood oral health.